For International Shipping Containers, the standard sizes are 20', 40', and 45' long by 96" wide, with exterior heights of 8 foot 6" or 9 foot 6". The shorter height is standard for 20 footers, while most 40 foot and all 45 foot cans are " High Cube ". All 40 foot reefers are now 9 foot 6" high, though the 8 foot 6" height was standard for years.
APL had some 48 foot X 96" wide dry box cans years ago, however I believe they were only for domestic double - stack use. The story at the time was that APL customers were receiving loads in 48 foot cans from domestic customers, then re - loading the 48 footers with international cargo, which would be refused at the pier. Highway overweights were also an issue with the 48 foot cans.